Future Propulsion Systems and Energy Sources in Sustainable Aviation

3Understanding Aviation’s Impact on the Environment

3.1 Introduction

Sustainability in the context of aviation is based on three inter‐related concepts: impact of aviation on environment (i.e. climate, air quality, and noise), the renewability of the energy sources, and the societal factors (e.g. economics) that increase our needs on air transportation. We begin with the first element of sustainability in this chapter. Aviation’s impact on environment starts at the ground level with air quality near airports and rises through Earth's atmosphere with greenhouse gas emissions. Aircraft engine emissions and noise impact air quality and health at the community level.

In addition to aircraft engines, auxiliary power units (APUs), the ground support equipment, ground access vehicles, construction activities, electric power plants, and maintenance operations are also deemed as emission sources that contribute to aviation‐related environmental pollution at the airports.

At the cruise altitude, greenhouse gases (GHG) in the engine emissions threaten to cause climate change through global warming. The impact of engine emissions on the climate in the form of nitrogen oxides (NO_x) threatens to deplete ozone in the protective ozone layer in Earth's atmosphere and generate harmful ozone at the ground/community level. The formation and spreading of persistent contrails in high‐flying jets is the source of aviation‐induced cloudiness (AIC), akin to naturally occurring cirrus clouds, which ...